1. Field of Invention
This invention relates to a workpiece positioner for positioning a plurality of workpieces in an efficient enhanced manner relative to an industrial robot. More particularly, but not by way of limitation, the invention is directed to a workpiece positioner with enhanced workpiece diameter capacity relative to positioner size and also includes a shield component.
2. Related Art
Workpiece positioners for welding parts similar to those welded by the positioner of the present invention have existed for a number of years. H-type positioners, for example, have long existed and include two parallel workpiece holders with an independent drive for rotating the workpiece holders about one axis and another drive for rotating the workpiece about another axis which is defined between rotational connection points of opposing arms of the workpiece holders. Such type is disclosed in U.S. Pat. No. 4,666,363, wherein the workpiece holder moves the workpieces so that the robot does not need to be moved during its operation and may be utilized to an optimum extent. This type has certain drawbacks in its design, such as, it only has a capacity for handling relatively smaller diameter workpieces to avoid interfering with a central cross-beam of the H-type structure which in turn negatively effects the operator ergonomics and robot working height.
Another design, as shown in U.S. Pat. No. 5,873,569, employs a rectangular type configuration which omits the central cross-beam in order to increase diameter of the workpiece which can be handled. However, this design also has similar limitations to the H-type in that increased diameter size of workpiece typically results in the enlargement of the overall structure of the workpiece positioner, operator ergonomics and rearrangement of the robotics involved.
Heretofore, an increase in diameter size workpieces caused significant retooling and increased expense. Another problem generated from increasing the size of such workpiece positioners is that the tolerances required are more difficult to maintain.
Accordingly, the present invention is an improvement over the art with increased capacity for handling increased diameter workpieces without the need for enlarging the space required for the workpiece holder and associated robotics as well as substantially obviating the need for height adjusting aids for workers using such workpiece holders and robotics.
It is an object to improve workpiece positioners.
It is another object to improve safety in a work place which uses workpiece positioners and robotics.
It is still another object to increase capacity for handling increased diameter workpieces without the need for enlarging the space required for the workpiece positioner and associated robotics.
It still another object in the field of workpiece positioners to minimize the height requirement for associated robotic""s programming and fixture maintenance and replacement.
It is another object to improve operator ergonomics in a work place which uses workpiece positioners and robotics.
Accordingly, the invention is directed to a workpiece positioner with the aforesaid objects in mind. The workpiece positioner includes a pair of generally vertically disposed laterally displaced and opposing workpiece holder supports and two pair of operably associated workpiece holders. Each pair of workpiece holders including a first and second workpiece holder which are operably associated with one of the workpiece holder supports such that the opposing first workpiece holders are generally coaxially aligned and the second workpiece holders are generally coaxially aligned. The workpiece holders rotate about a first generally horizontal common axis with respect to the vertical workpiece holder supports. Further, the first workpiece holders and the second workpiece holders, respectively, are disposed at least partially on an opposite side of a plane which runs generally perpendicular to the vertical workpiece holder support and through the horizontal common axis.
Preferably, the workpiece holders are interconnected by a support tying member, to form a U-Shaped or rectangle member, which is configured to provide a minimal clearance region between two workpieces operably disposed on the workpiece holders. The support tying member can be further characterized to extend through the minimal clearance region in a manner to serve as a shield between workpieces. There are further included holder drive means for selectively rotating the workpiece holder about the first horizontal common axis and workpiece drive means for selectively and independently rotating each workpiece about a second axis between the first workpiece holders and a third common axis between the second workpiece holders.
Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.